Pencil-sharpener



C. S. STORRER.

PENCIL SHARPENER.

APPLICATION FILED SEPT- 1. 1914. RENEWED MAY 20, 1919.

1,3 2,055, Patented Dec.14,1920.

3 SHEETS-SHEET i- C. S. STORRER.

PENCIL SHARPENER. APPLICATIONHLED SEPT-1,.l9l4. R-ENEWED MAY 2o,19 |9.

3 SHEETS-SHEET 2- Patented Dec. 14, 1920.

C. S. STORRER.

PENCIL SHARPENER.

APPLICATHIIN FILED SEPT-1,19i4. RENEWED MAY 20,1919.

Pat

ented Dec. 14, 1920.

3 SHEETSSHEET 3.

W565: Rye/ZZZ]?- UNITED STATES PATENT OFFICE.

CARL S. S-TORRER, OF'WINTERTHUR, SWITZERLAND.

PENCIL-SHARPENER.

Application filed September 1 1914, Serial No. 859,625.

To all whom it may concern:

Be it known that I, CARL S. S'ronRnR, a citizen of the Republic of Switzerland, residing at l/Vinterthur, Switzerland, have invented new and useful Improvements in Pencil-Sharpeners; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

Machines used for sharpening lead pencils, colored pencils and the like, which act upon the wooden shaft and the core of graphite, color and the like, are already known. In the hitherto proposed pencil sharpeners the wooden shaft and the core of the pencil are acted upon in a single cutting plane, so that it is impossible to obtain a sharp, lengthened graphite or color point and the latter cannot be sharpened in any desired manner.

The object of this invention is to provide a machine for sharpening lead pencils, col.- ored pencils and the like, in which the hereinbefore mentioned drawbacks are eliminated. To this end there is imparted according to this invention to at least one knife having a stepped or broken cutting edge such a relative movement with respect to the lead or color pencil, that said edge is brought to act at first during a course of work in a cutting plane upon the wooden shaft and afterward in a plane, which is different from the first mentioned one, upon the core of graphite and color respectively. In other words, a cut is produced on the pencil in a broken line, 2'. 6., a line formed of a number of lines joined at their ends and not forming a continuous straight line, said broken line extending from the periphery of the pencil to or through the axis thereof.

In the accompanying drawings:

Figure 1 is a front elevation partly in section of a first embodiment of the invention,

Fig. 2 is a horizontal section on the line 22 of Fig. 1,

Fig. 3 is a side view of this sharpener,

Fig. 4 is a vertical section on the line 44 of Fig. 1,

Figs. 57 show front elevations of different shaped cutting knives,

Specification of Letters Patent.

Patented Dec. 14, 1920.

Renewed May 20, 1919. Serial No. 298,556.

Figs. 8-10 show these knives in their different working positions relatively to the lead pencil and colored pencil respectively,

Fig. 11 is a vertical section of the pencil holder,

Fig. 12 is a horizontal section on the line 12-12 of Fig. 11,

Fig. 13 is a top view of the feeding mechanism for the revolving sleeves of the pencil holder. 4

The embodiments of my invention illustrated in the accompanying drawings comprise a box-like receptacle 1 provided with a drawer 2 for the shavings. To the top of the receptacle 1 is fixed a two-parted casmg 3 supporting a horizontally mounted shaft 4. To this shaft 4 is fixed outside the casing 3 a crank 5 and inside said casing a cam disk 6 having three equally shaped lifting cams 7 formed by providing a correspondingly shaped lateral slot 8 milled out of the cam disk 6. Each lifting cam 7 has a steep lifting curve 7 and an adjacent less steep lifting curve 7 as well as a steep downward sloping curve 7 The curve 7 of each of said lifting curves 7 imparts a quick movement to the knife carrier relative to the wooden shaft of the pencil, while the second (7 of these curves imparts to the knife carrier a slower movement relative to the core of graphite or color of said pencil. The downward sloping curve 7 causes a quick return movement of the knife carrier (Figs. 1, 2 and 4).

A roller 9 mounted on an arm 10 projects into the slot 8. The arm 10 is fixed to a horizontal shaft 11 supported in the front wall of the casing 3. To this shaft 11 is fixed the knife carrier consisting of an arm 12. This arm carries on its upper end a de fiection 12' lying in the plane of this arm and having a bearing surface for a knife 13; said bearing surface is arranged obliquely with regard to the path of movement of the arm 12 and it has two noses 14 projecting into corresponding recesses 15 provided in the knife and serving for securing the'latter in its proper position. to the arm 12 by means of a clamp screw 16 screwed into the deflection 12' and a clamp plate 17 resting on the knife and acted upon by the head of said screw 16. (Fi 5. 1-3).

U pon a rotation of the cam disk 6 in the direction of the arrow shown in Fig. 1 the arm 12 iscaused to swing by each of the The knife is secured three lifting cams of the curved slot 8 from. the upper position shown in Fig. 1 in full lines into the position shown in point and dash lines and it is then afterward returned into its normal position. Thereby the downward movement of the knife carrier, which corresponds to the cutting motion of-the knife is effected by steps and at different speeds in accordance with the different steep slopes of the lifting curves 7 and 7 of the lifting cams 7.

On the level of the shaft. f there is mounted in the casing 3 a pencil holder 18. The latter is carried by an arm 19 attached to the casing by Ineansof a screw 20 and secured against displacement by means of a pin 21 fixed to the holder 18. The holder 18 is adjustably mounted on a bolt 22 screwed into the arm 19, the pin 21 preventing thereby an accidental rotation of this holder 18. A spring 23 surrounding the bolt 22; presses the holder 18 against the arm 19. For the purpose of rotating the holder 18, there is fixed to it a button 2 1, so that this holder 18 can be moved outward against the action of the spring 23 and shifted in the longitudinal direction of the bolt 22. The pencil holder 18 has two borings 25 and 25 of different size to receive lead and colored pencils of different thicknesses. These two borings are parallel to each other and they form an angle with the planeof movement of the knife. They have the shape shown in Fig. 11, 2'. 6. they consist of cylindrical and tapered longitudinal parts. The cylindrical outer part of each boring acts as a bearing for a revolving sleeve 26 or 26 respectively, provided with a feeding wheel 27 or 27 respectively, fixed to this part and having also resilient wire clamps 28 or 28, respectively. The clamps 28 or 28 respectively, are jammed tightly bei tween a flange of the sleeve andthe feeding :respectively,

cam disk 6 three noses .30 lying. opposite ratchet wheel 27.

wheel and the free, resilient shanks or legs of tl1m'p1O]8Ct through slots of the sleeve 26 or 26 respectively, into the boring of the latter (Fig. 12). These resilient clamplng shanks holdfast the lead orcolored pencil inserted into the sleeve 26 or 26 respectively. To retain the sleeves 26 and 26 in the borings 2 5 and 25 there are fixed to the holder 18 flat stirrups 29 and 29' passing over the feeding wheels 27 and 27. .The sleeves 26 and 26 of theholder 18 maybe. moved by jerks in the borings-25 and 25". To this end there are provided on the circumference of the the lifting. cams 7 and actuating an.operat ing. lever 31 v (Fig. 13), which carries a spring controlled pawl' 32 engaging the The sleeves 26 and 26 are rotated whenever the knives 13 act upon the pencil, 2'. 0. while the knife carrier'12 is moved back into its upper position.

The corresponding ends of the borings 25 and 25' lie in two parallel planes 18 (Fig. 11) of the holder 18. One of these planes (in the embodiment of the invention shown is the plane in which lies the end of the boring 25)' corresponds to the plane of movement of the knife, while the other one of said planes lies opposite the first mentioned plane (Fig. These sides or planes 18' touch the outermost mantle-line of the conical longitudinal parts of the borings 25 and 25 (Figs. 3 and 11). The holdler 18 has also stops 33 and 33 limiting the feed of the pencil in the borings 25 and 25.

Beneath the knife carrier there is provided in the receptacle 1 an opening 3 1 and above this opening is fixed a sheet iron plate 35 guiding the shavings whittled away duringthe course of work of the knife toward the opening 3 1, so that they may fall into the drawer 2 (Figs. 2 and 1).

Figs. 57 illustrate three knives 13, which have two-stepped cutting edges of different shape and which may be used in the hereinbefore described machine. The knife shown in Fig. 5 has a stepped cutting edge 36, 37, while the knives shown in Figs. 6 and 7 have broken edges consisting of a straight part 36 and a' part 38 or 39 respectively, which is situated in a differentplane than the straight part 36. The cutting edge 36 of the three knives shown serves to Whittle away the wood in one plane, while the cutting edges 37-39 serve 100 to cut off the core of graphite or color in a different plane. The edges 36 and 37 of the knife illustrated in Fig. 5 are parallel to each other, while the edge 38 of the knife shown in Fig. 6 has a curved and con- 105 cave shape and the .edge 39 of the knife shown in Fig. 7 is inclined with reference to the edge 36. The knife is set at an angle of about 15to the plane or .movrnent while the cutting edge 36 is beveled at an anglellO of 15 to' the plane in which the knife is set and the edges 37-39 are beveled at an agkn ife of the type shown in Fig. 5 has to be used. if this is the case the pencil is'insertedas shown in the drawings, into the sleeve 26' of the holder 18, the cain disk6 is then rotated by means ofthe crank 5 in the direction of the arrow shown in; Fig; 1, the lifting cams? acting'thereby one after another upon the knife carrier 12. The latter is thus oscillated to and fro together with the knife. Upon each downward movement of the knife carrier the edge 36 of the knife 13, which is moved from the posit-ion I shown in Fig. 8 downward, whittles away a shaving from the wooden shaft of the pencil projecting beyond the side 18 of the holder 18. Owing to the fact that the knife cuts thereby the axis of the pencil along a circular line, the cutting edge 36 comes at a certain moment out of contact with the wooden shaft of the pencil (position II, Fig. 8) before the cutting edge 37, which is set back with respect to the edge 36, begins to act upon the core of graphite, so that a part of the latter will not come in touch with said edge. This part of the core maintains therefore its full cross-sectional area. Only after that the cutting edge 37 has been moved into the position III, it will begin to act upon the graphite core and cut off the graphite in the same manner as the edge 36 whittles away the wooden shavings. In the position IV the cutting edge 37 comes then also out of contact with the graphite core and the knife is again moved upward, one of the noses 30 acting thereby upon the feeding device 31, 32, 27, so that it causes a partial rotation of the pencil. It will be seen by referring to Fig. 8 that the line of cut is a broken one as the line from I to IV is not straight. The straight line from I to II and the straight line from III to IV are not continuous, but are joined at their adjacent ends by the line from II to III.

In this manner the pencil is graduallyacted upon all around by the two edges 36 and 37 of the knife, which begins to cut out a core as well of the wooden shaft as of the core of graphite. Afterward the knife pushes the pencil to a certain amount downward and the latter is then again acted upon all around by said knife. The sharpening operation proceeds in this manner till the graphite point strikes against the stop 33, in which case the pencil point will then have the desired shape. If an unsharpened pencil has to be sharpened, the cutting edge 36 whittles away all around the wooden shaft till the core of graphite is laid bare, whereupon the latter is cut off in the hereinbefore described manner by the cutting edge 37, the wood being whittled away during the same course of work by the cutting edge 36. In accordance with the shape of the lifting cams 7 and the slot 8 respectively, the cutting speed of the knife of the hereinbefore described machine will be greater during the first cutting phase when the edge 36 is beveled at a small angle with respect to the wooden shaft to be cutoff, and it will be smaller during the second cutting phase, when the edge 37 is beveled at a greater angle with regard :tothe harder core of graphite. In this latter case the graphite core will be more scraped off than out off.

If a knife of the kind shown in Fig. 6 is used the pencil will be sharpened in the manner shown in Fig. 9, 2 e. the cutting edge 36 of the knife 13 cuts off a shaving of the wooden shaft along a straight line upon said edge being moved from the position I into the position II, while the cutting edge 38 moved from the position II into the position III cuts the core of graphite along a curved line deviating from the straight cutting direction of the knife. Here also the cut from I to III is in a broken line. Thus, the sharp ening machine begins to cut a core out of the wooden shaft and a point having a convex outer surface out of the core of graphite.

If a knife of the kind shown in Fig. 7 is used, a core will be cut out of the wooden shaft b I the edge 36 while the knife is moved irom the position I into the position II (F ig. l0) and upon a movement of the knife from the position II into the position III the cutting edge 39 begins to cut a conical shaped point out of the core of graphite, the mantle-line of said point forming then a broken line with the mantle-line of the wood-cone.

Instead of moving the knife with respect to the pencil along an are shaped line, it may as well be moved along a straight line cutting the axis of the pencil.

The resilient shanks or legs of the wire clamps 28 and 28' of the holder 18 can not only give way radially, but they may also give way outward in a lateral direction to permit the insertion of round pencils and of pencils having eight edges as well as of six cornered pencils into the sleeves 26 and 26, in which they are held'fast by said clamps 28 and 2S. 1 v In the hereinbefore described machine for sharpening pencils there is obtained a lengthened sharp point of the core of graphite or color forming the continuation of the lengthened wooden cone of the pencil.

What I wish to claim is:

1. In a machine fqr sharpening lead pencils and the like, a knife having cutting edges in different planes, a pencil holder, and means for moving the knife in a plane longitudinally of the pencil to produce a shearin cut, one of said cutting edges acting at fIrst during each course of work in a cutting plane upon the wooden shaft, the other of said cutting edges subsequently acting on the core in a cutting plane, which differs from the first mentioned one.

2. In a machine for sharpening lead pencils and the like, a knife having cutting edges in different planes, a knife carrier, a pencil holder, and means for moving the knife carrier longitudinally of the pencil to produce a shearing cut at varying speeds with respect .to the wooden shaft and the adjacent cutting edges arranged in the longitudinal direction of the knife and having different bevels, a knife carrier, a pencil holder, and means for moving the knife carrier longitudinally of the pencil to produce a shearing cut, said knife acting first on the shaft with the one of saidcutting edges and afterward with the other one of said edges upon the pencil core.

4. In a machine for sharpening lead pencils and the like, a knife, provided with a stepped cutting edge, the two parts of the edge having different bevels', a knife carrier, a pencil holder, and means for moving the knife carrier longitudinally of the pencil to produce a shearing cut at varying speeds with regard to the wooden shaft and the pencil core, the projecting part of the cutting edge having a small bevel acting at a great speed in a cutting plane upon the wooden shaft, while the other part of said cutting edge having a greater bevel acts afterward upon the core at a smaller speed in a cutting plane, which differs from the first mentioned one.

5. In a machine for sharpening lead pencils and the'like, a knife having two adjacent cutting edges arranged in the longitudinal direction of the knife, a movable knife carrier, clamps ,for securing the knife to said carrier, a pencil holder and means for moving the knife carrier transversely and longitudinallyof the stationary pencil at varying speed with respect to the wooden shaft and the pencil core along a line cutting the axis of the pencil, one of said cutting edges acting at a great speed upon the wooden shaft, while the other one of said edges acts afterward at a smaller speed upon the pencil core, the two cutting planes being different from one another.

6. In a machine for sharpening lead pencils and the like, a pivotally mounted knife carrier, a knife consisting of athin blade of steel having a stepped edge, the two stepped portions of which have different cutting edges, means for securing the knife to said carrier, a pencil holdercomprising a rotatable sleeve to receive the pencil and wire clamps for holding the pencil, a re volving cam diskhaving a lateral curved slot, a roller on the knife carrier projecting into said slot, said slot being provided with a plurality of lifting cams, each of which has a steep and a less steep lifting curve for the knife'carrier so that the latter is moved transversely and longitudinally of the pencil upon a rotation of said cam disk, the projecting part of the cutting edge having a small bevel acting first on theshaft at a great speed in one cutting plane, the other part of said cutting edge subsequently acting on the core at a smaller speed in a cutting plane which differs from the first mentioned one, and means for revolving the sleeve together with the pencil during the return movement of the knife carrier.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

CARL S. STORRER. Witnesses:

CARL OUEVIER, ALBERT KORTE. 

